The purposes of this cooperative agreement are to establish a community HIV/AIDS surveillance and monitoring system in Rio de Janeiro, and to develop, implement, and evaluate a community-based HIV/AIDS prevention/intervention program for injection drug users (IUDs). The proposal is being submitted through the Center for Drug and Alcohol Studies at the University of Delaware, with a subcontract to NEPAD (Nucleo de Estudos e Pesquisas em Atencao ao Uso de Drogas), a non-profit drug treatment and research center affiliated with the State University of Rio de Janeiro. A total of 2,400 subjects will be recruited (60% male; 40% female; 50% white; 50% black/mulatto) and tested for the presence of HIV-1. Of this pool, 2,100 will be randomly assigned into one of three different levels of HIV/AIDS prevention/intervention: Level-1, composed of interviewing with the Risk Behavior Assessment (RBA) questionnaire and related instruments, serologic testing, and pre- and post-test counseling; Level- 2, composed of the Level-1 elements plus a 90-minute enhanced intervention immediately following post-test counseling; and Level-3, composed of the Level-2 elements plus a 60-minute booster session at first follow-up. All 2,100 study subjects will be followed-up at the end of 6 and 12 months for reassessment and testing for HIV-1, with an expected capture rate of 86%. Other components of the project include: training representatives from Rio de Janeiro's many civic, church, and community groups in various aspects of AIDS education, and mobilizing a coalition of these groups for the purpose of accelerating a city-wide HIV/AIDS prevention/intervention effort; conducting an ethnographic study in drug-using networks; and compare the methods, efforts, and experiences in Rio de Janeiro with those of three other AIDS outreach projects targeting hard-to-reach populations (Belle Glade and Miami, Florida and San Juan, Puerto Rico). Process evaluation will focus on the procedures of program implementation. Analysis of variance and regression techniques will be used to assess the effectiveness of the interventions. Structural equation models will be used to examine the characteristics that account for positive changes. The significance of the proposed project relates to the high rate of AIDS in Brazil; the extent of injection drug use in Rio de Janeiro; the HIV risk behaviors engaged in by local drug users; the extent of HIV infection in Rio de Janeiro's high-risk populations; the need for HIV/AIDS prevention programs in Rio de Janeiro in general, and in local favelas (shantytowns) in particular; and the potential for the transmission of HIV infection from segments of Rio de Janeiro's high risk groups to other populations.